Fluid circuits, such those used in refrigeration and heat pump circuitry, may use a restrictor for controlling the flow through the conduit. The restrictor may be for the purpose of controlling the rate of flow in one direction and permitting unrestricted flow in the other direction. An example of a uni-directional flow control device in the form of a floating restrictor is shown U.S. Pat. No. 4,896,696 issued to Bradley, et al., on Jan. 30, 1990 and is hereby incorporated by reference. However, in a heat pump, the change from the cooling function to the heating function, and vice versa, is achieved by reversing the direction of refrigerant flow in the system. This requires by-pass conduits and check valves to be used with a uni-directional flow control device in each flow direction.
Bi-directional flow control has been accomplished by using two floating restrictor devices back-to-back as shown in U.S. Pat. No. 5,265,438 issued to Knowles, et al. on Nov. 30, 1993 and is hereby incorporated by reference. The bi-directional flow control devices eliminate the need for by-pass conduits and check valves to redirect flow on a change from the cooling function to the heating function.
However, the bi-directional flow device requires two floating restrictors and associated cartridges. It would therefore be a significant advantage over the prior art to provide bi-directional flow control using a flow control device with a single floating restrictor.
Another problem with floating restrictor devices is that may produce relatively high velocities adjacent the restrictor, and it is common for operational noises to be generated. Such noise may be in the form of a rattle, or other vibrations produced by the flow and turbulence of the fluid as it passes around and through the restrictor.
It would therefore be a significant advantage over the prior art to provide a floating restrictor having an anti-rattle mechanism.